In some vertically movable workpiece support devices, the drive chain is configured so as to support the workpiece support base in a vertically linear path section extending from one end portion coupled to the workpiece support base to an intermediate portion engaging with the driving sprocket wheel, and this type of vertically movable workpiece support device has been utilized by installing the device on a conveying traveling body, for example, in order to change the height of a workpiece which is placed on the workpiece support base to be conveyed, in a predetermined section on a conveying path. In the vertically movable workpiece support device described above, as described in Japanese Published Unexamined Patent Application No. H07-017694 (Patent Literature 1), the drive chain engages with the driving sprocket wheel in a range of approximately 90 degrees between a position directly below the driving sprocket wheel and the lower end of the vertically linear path section. However, in order to prevent a failure in which the drive chain engaging with the driving sprocket wheel is disengaged from the driving sprocket wheel by part of thrust received from the driving sprocket wheel so as to be displaced outward and in which the engagement depth of the drive chain with respect to the driving sprocket wheel becomes shallow, a chain guide plate is additionally provided which is fitted between links on both left and right sides forming the drive chain so as to make contact with a link-to-link roller.